Abstract: The invention discloses an apparatus for enhancing light absorption of solar cells and photodetectors by diffraction. The invention comprises the structure as the plurality of nano-level well-arranged arrays with a plurality of certain defect areas including the shapes of rod, tapered-cone, and cone, which diffracts incident light to oblique angles for light trapping. Surface reflection can also be reduced for either broadband or narrow band spectral absorption. The increased contact area between the transparent conducting layer and photoactive layer is beneficial for current extraction, which increases the internal quantum efficiency (IQE).

Abstract: The present invention provides an optical touch display device, an optical touch sensing device, and a method for calculating a touch position. The optical touch sensing device can be detachably attached on a display panel using adhesive or other method. The present invention includes a first light source, a second light source, a light sensing element, and a processing unit. When an object blocks the path of light, some light sensing elements will receive some or no light. The processing unit will then compute two line segments based on the positions of light sensing elements receiving some or no light. The two line segments cross each other and their intersection is defined as the position of object or the touch position.